(1) Field of the Invention
The present invention pertains to a shoe sole construction in which an aperture provided through the shoe sole is covered over by a composite support plate. The support plate in turn is covered over by a pad having a peripheral dimension larger than the support plate. The pad cushions the support plate so that its presence in the shoe sole is not detected by the shoe wearer's foot.
(2) Description of the Related Art
In the construction of shoe soles, composite materials such as fiberglass, graphite, and fiber-reinforced polymeric materials are being used in various different forms and for various different purposes. For example, U.S. Pat. No. 5,052,130 discloses a shoe sole that employs a spring plate in combination with its midsole. The spring plate is constructed of multiple layers, with each layer comprised of parallel carbon fibers imbedded in polymer. The fibers of successive layers are positioned at acute angles relative to each other giving the spring plate a stiffness that is anisotropic, being greater longitudinally than laterally. The spring plate formed in this manner provides the shoe with rearfoot stability, impact cushioning, arch support and forefoot propulsion. U.S. Pat. No. 4,878,300 discloses an athletic shoe having a sole comprised of parallel midsole layers with a shock dispersing plate disposed between the layers. The shock dispersing plate is constructed of fiberglass material. The plate covers over vertical openings centered within the heel area of the sole which penetrate the midsole and outsole layers and permit the shock dispersing plate to yield in the area of the openings. U.S. Pat. No. 5,319,866 discloses a composite arch member employed in a shoe sole where the arch member is constructed of a carbon-glass weave. The arch member provides support to the arch region of the foot and replaces midsole material which is removed from the arch area of the midsole to reduce the weight of the shoe sole.
While the use of fiberglass or graphite fiber composite plates in the construction of shoe soles provides beneficial characteristics to the shoe sole such as increased strength and reduced weight, frequently the comfort of the shoe wearer's foot on the shoe sole incorporating a composite plate is overlooked. It is an object of the present invention to provide a simplified shoe sole construction that includes a graphite/polymer composite plate that provides strength to support the shoe wearer's foot without sacrificing the comfort of the shoe wearer's foot.